blackhole

listen to the pronunciation of blackhole
Английский Язык - Английский Язык
A resource sink
A bit bucket; a place of permanent oblivion for data
DNSBL, used to block spamming IP addresses – are often called "blackhole lists"
Alternative spelling of black hole, especially in the attributive
A place where traffic is silently discarded
A blackhole server, a DNS server that handles reverse lookups of invalid IP ranges

One way of fighting spam is to use a blackhole list maintained on a blackhole server.